The rebels had remotely detonated a bomb at one of the base’s gates the day before, but were pushed back by the army, according to both the Observatory and a military source inside the airbase.

The military source said that clashes outside Taftanaz had been non-stop for more than 48 hours and there had been a large number of rebel casualties.

Three rebels were also killed by troops around the Deir al-Zor military airport, as fighting broke out in the provincial capital in the east of the country.

In the town of Mleha, just east of Damascus, bodies were being recovered from a service station hit by a regime air strike on Wednesday.

The Observatory said at least 12 bodies were recovered, several of them rebels.

The Local Coordination Committees, a grassroots network of activists, estimated that at least 50 people died in the attack.

The Observatory said 160 people were killed in violence across Syria on Thursday, including 72 civilians, almost half of whom were women and children.

On the humanitarian front, a 33-truck aid convoy organised by Turkish and Qatari relief groups left Istanbul on Thursday carrying 850 tonnes of flour.

‘‘[The] regime is bombing the bakeries and there is a very huge need for flour in Syria,’’ Huseyin Oruc, the vice-president of the Turkish IHH Humanitarian Relief Foundation, said.

One of Syrian President Bashar al-Assad’s main allies, Hassan Nasrallah, chief of the Shiite militia Hezbollah in neighbouring Lebanon, warned in a televised speech on Thursday that Syria was threatened with ‘‘schemes of division and partition’’.